Achieving smooth motion and high-speed for piezoelectric stick-slip actuator based on the two-stage lever principle

With the development of the precision manufacturing industry, actuators' performance requirements are increasingly demanding. However, stick-slip actuators still have the problems of backward motion and low motion speed at low frequencies. In this paper, to decrease the backward motion and achieve high speed at low frequencies, a linear piezoelectric stick-slip actuator is designed based on the two-stage lever principle. Theoretical and numerical investigations are used to optimize the flexible hinge of the stick-slip actuator. Experimental results indicate that the motion slider can achieve a smooth motion. The backward rate can even drop to 0. The maximum motion speed was 124.83 mm/s at 1600 Hz. The motion speed of the designed actuator was higher than that of previous stick-slip actuators at the same frequency. In addition, the load capacity of the prototype is tested. Based on different loads, the load matching is achieved by an auxiliary piezoelectric-stack, where the maximum horizontal load was 2.3 N. According to the comparison with previous actuators, the designed prototype can achieve high speed at low frequencies. Furthermore, the displacement curves show good smoothness. These characteristics will be helpful for the practical application of stick-slip piezoelectric actuators.